Brain Cancer

Overview

Brain cancers in children are usually primary brain cancers, while brain cancers in adults are mostly secondary brain cancers that have metastasized (spread) from other parts of the body. The most common primary brain cancers are tumors known as gliomas, which originate in glial cells in the brain and spinal cord. Glial cells surround nerve cells and keep them in place.

The gliomas include astrocytomas arising in star-shaped glial cells called astrocytes, brain-stem gliomas occurring in the lowest part of the brain, ependymomas arising from cells that line parts of the spinal cord, and oligodendrogliomas arising from cells in the brain that make fatty substances that protect nerves.

Other types of brain cancers originate elsewhere in the brain. The most common ones are medulloblastomas arising in the part of the brain called the cerebellum, meningiomas arising in the meninges (the membranes covering the brain), schwannomas arising from cells that line the nerve that controls balance and hearing (Schwann cells), craniopharyngiomas occurring at the base of the brain, germ-cell tumors arising from cells in the brain known as germ cells, and pineal region tumors arising in or near a gland in the brain known as the pineal gland.